Telephone set



Feb. 17, 1942. D, ,4, IN 2,273,530

TELEPHONE S ET Filed March 30, 1938 2 Sheet-Sheet 1 a o "'IIIIIIII aw;

INVENTOR D. H. K/NG 8;

WWW

A 7' TORNEV Feb.-17, 1942.

' D. H. KING TELEPHONE SET Filed March 30, 1958 2 Sheets-Sheet 2 INVENTOP ATTORNFV Patented Feb. 17,1942

mane

TELEPHONE sar Douglas H. King, Maplewood, N. 3., assignor to Bell Telephone Laboratories,

Incorporated,

New York, N. Y., a corporation of New York Application March 30, 1938, Serial No. 198,825

, 12 Claims.

This invention relates to telephone apparatus and particularly to improvements in subscribers telephone sets.

The objects of the invention are to increase the usefulness-of telephone sets; to facilitate the acts required to manipulate them; to simplify their structure and operation; and to secure a of which the subscriber may establish and dis establishtelephone connections between his station and extension stations associated with his ownline. Also, it has been common practice to provide the stations in an intercommunicating system withkeys or buttons for making connections.

In the copending application by A. Tradup, Serial No.'198,819, filed March 30, 1938, now Patent No. 2,212,216 issued Aug. 20, 1940, is disclosedand claimed a system for preventing listeningin by extension stations. In this system there are provided two plungers in the cradle of a. desk stand whereby the lifting of the handset from the cradle releases one plunger to operate. the usual line spring contacts to connect the telephone set with the line and in which the subsequent manual lifting or raising of another plunger causes the operation of so-called secrecy contacts to open the extension telephone connection to secure privacy on the line calling and in which the replacing of the handset on the cradle restores the two plungers and associated contacts to normal position.

It is a feature of the present invention to provide an improved arrangement in telephone sets such as are disclosed in the above-mentioned copending application for performing the desired switching operations. For example, the plunger operated switch may serve tocontr'ol the connection anddisconnection of an extension station. To this end the telephone set which'is provided with two plungers in the cradle the same. as in the Tradup system for controlling line circuit contacts and secrecy contacts, is arranged so that the subscriber'may flash the line contacts by the operation of eitherplunger if the ated without disturbing this setting and at the same time retain the feature of causing the restoring of both plunger and their associated sets of contacts to normal on the replacing of the handset on the cradle.

A special feature of this invention is the arrangementof a loose collar on the secrecy plunger whereby incasethe secrecy contact operating plunger is operated to fiash'the line contacts, the accidental operation of the secrecy contacts is avoided.

The invention has'been illustrated in the accompanying drawings, in which:

Fig. lis. a perspective of a desk stand forintor-communicating telephone sets provided with adial for establishing connections to a central office, keys for establishing connections to intercommunicating lines and plungers equipped in accordance with the'present invention; Figs; 2, 3, 4 and 5 show the detail construction of the two plungers in the cradle and the contact arrangements controlled'thereby;

Fig. 6 shows the special feature cfapplicants invention-relating to the loose collar on the setheoperation of the lin contact'operatingplunger only if the secrecyrcontactshave beenopercrecy contact operating plunger;

Figt'lshows in diagrammatic form two regular telephone stations and an extension station equipped in accordance with the applicants invention with the circuits of an intercommunicatingline between these two stations and plunger equipment for excluding the extension station; and

Fig. 8 showsthe detail circuit arrangement of one subscribers telephonev station and an associatedextension station, and the circuit for one line extending from these stations with associated pich-up key anda pick-up keyfor another line.

Referring now particularlyto-Fig. 1, the desk stand may consist of a base [on which are shown keys 2 for establishing connections between stations and a dial 3 for calling over a line to a central office. This base also is provided with four upwardly extending prongs 5 forming a cradle in which the handset 6 rests when the telephone is not in use. Between-the left-hand prongs in this figure is shown a plunger lwhich mayoontrohthe linespring contacts and between the-right-hand prongs 5 is shown a plunger 8' which may controlthe secrecy contacts. Referring now to the detail construction of the plungersl and 8 and the contacts operated thereby; as shown in Figs. 2 to 5, Fig; 2 'is a vertical crosssecti'on taken through the center of-the cradle of Fig; 1 exposing the two plungers' l'andB. These plungers are shown in the released positions they occupy when the handset is removed from the cradle. The plunger "I is inserted in an aperture in the casing I and is provided with a lower shoulder Ill to limit its upward movement. This plunger I operates on a lever II pivoted on a shaft I2 journaled in bearings I3 of the casing I. The lever II is extended in the shape of a bracket that straddles the bearings I3. Fig. 3 shows a side View of this plunger I and associated contacts taken on line $i--3 of Fig. 2. Lever II engages the under surface of the collar III at I 4 and the bracket portion thereof is provided with an angular extension I5 to which is attached an insulating knob I8 which operates on the line spring contacts II. These contacts may be supported in any suitable manner in the casing I. When the plunger is in the position shown in Figs. 2 and 3, these contacts are closed and when the plunger is depressed by the replacing of the handset, the contacts II are opened. The closed condition of the contacts I! is shown clearly in Fig. 4 and comprises two sets of individual line contacts.

The plunger 8 is also inserted in an aperture in the casing I, as shown in Figs. Z-and 5, Fig. 5 being a cross-section taken on line 5-5 of Fig. 2. In these Figs. 2 and 5 the plunger 8 is shown in the raised position that it occupies when the handset 65 has been removed from the cradle. This plunger 8 is provided with a lower shoulder I9 and is raised to the position shown by the lever 29 pressing against the under surface of this shoulder. This lever is pivoted on the shaft I2 and has an extension 2! which in this position of the plunger engages the lower bracket portion of the lever II at the point 22. The plunger 8 is therefore raised in the position shown in Figs. 2 and 5 in the same manner as plunger I is raised when the handset 6 is removed from the cradle by the lever II. The plunger 8 is also provided with an extension 23 which is circular in cross-section and ends in a coneshaped portion 24 which in the position shown engages the springs 25 and 26. The spring 25 operates on contacts 28 and spring 26 operates on contacts 29 so that when the plunger 8 is lifted further manually by gripping at the point where the plunger is reduced in diameter to form an upper knob 3|, the cone-shaped portion 24 is pressed between the springs 25 and 26 to separate them. When the plunger 8 is lifted in this manner, these springs close connections between the contacts 28 in one case and 29 in the other case. The cone-shaped portion 24 is raised sufliciently to be held between the springs 25 and 26 until it is released by depressing the plunger 8 manually, or by the replacing of the handset on the cradle.

It should be noted, therefore, that when the handset is removed from the cradle and the plunger I is raised, the plunger 8 is also raised to the position shown in Figs. 2 and 5, but it should be observed that in this position it does not operate the contacts 28 and 29 and it is from this position that the contacts 28 and 29 may be manually operated as described.

If the subscriber depresses plunger I to alternately open and close the contacts II to flash the line, it should be noted that if the plunger 8 has been raised to operate its contacts 28 and 29, this raised position of the plunger 8 will not be disturbed by this movement of the plunger I as the lever II merely moves in a direction away from the extension 21 on the lever 20 at point 22. Lever II, therefore, does not disturb the position of the lever 20 in its relation with the plunger 8 regardless of where it is located at the time, whether it is merely raised, as shown in Fig. 5, or further raised as shown in dotted line in this figure for the operation of contacts 28 and 29. If plunger 8 has not been manually raised to operate contacts 28 and 29, the subscriber may also operate the line contacts IT by alternately depressing and releasing the plunger 8. In this case the plunger 8 depresses the lever 29 which then engages at the point 22 by its extension 2I the cradle portion of the lever II and causes it to be operated to flash the line contacts I1. It is, of course, understood that in case the subscriber wants to flash the operator by depressing the plunger 8 from its raised position in which it has operated contacts 28 and 29, it will first release these contacts and then cause the line to be flashed as described by the lever 20 acting on the lever I I.

In Fig. 6 the special loose collar arrangement which constitutes another feature of applicant's invention has been shown. In this Fig. 6 a special collar 32 is inserted between the shoulder 33 and the shoulder I9 on the plunger 8. This collar 32 is movable between these two shoulders and is comparatively heavy. The purpose of this collar is to prevent the accidental operation of the contacts 28 and 29 in case the plungers are used for flashing. It operates as follows: If the subscriber in depressing and releasing either plunger should allow them to snap upward the lever H will move as far as its stop surface permits. Link 20 on the other hand is not so limited and is therefore free to continue its upward movement and may permit plunger 8 to rise beyond the position it occupies when the handset is removed from the cradle. Should the pressure of springs 25 and 26 not be sufiicient to retard the plunger 8 from such continued upward movement these springs may, if it were not for the collar 32, be spread apart sufficiently to cause false operation of contacts 28 and 29. However, this is positively prevented, due to the difierence in the masses between the plungers 8 and collar 32. Under these circumstances the collar 32 will leave the shoulder I9, move upward at a greater speed and independent of plunger 8 and eventually strike the edge 34 of the casing I and rebound downward to strike the shoulder I9 and thus counteract and stop the slower upward movement of plunger 8 before the contacts 25 and 28, 26 and 29 have had time to operate falsely.

Fig. 7 shows this desk stand as described above employed in an intercommunicating telephone system. A single line arrangement for two regular set stations and an auxiliary station have been shown in this figure. It should be observed, however, that this line and its connecting contact equipments have only been shown diagrammatically in this figure to merely illustrate the general principles of the communication facilities that may be used in connection with the applicants invention while in Fig. 8 the circuit arrangements of this kind have been shown in detail. A description will now be made of the operation of this system in connection with Fig. 7. 34 and 36 are regular sets equipped with keys 31 and 38, respectively. The operation of any of these will select corresponding lines and the removal of a handset 6 will complete the telephone circuit from a calling subscribers set to a selected line. For example, if the subscriber at station 3.5; removes. his; handset. from; the cradle his plunger 4.0:whichi'correspondsztoythe plunger 1: WflllbB? raised astdescribed and close; a'.c.onnection ,for.theztransmitterrand; receiverzin the hand set throughtm thezkeys 3.11:. Thessubscriber: may then. operate; inn example the. leiti-hand. key to connect his: telephone set. to; the: line. 45, which may: be: the: line amending to.station .36: and Suitable circuits may; be; provided: for ringing: the. called party/ at; thisgstatiom. When. the: subscriber at station: 36? removes-.ahis handsettfrom the-cradle a talkingwconnectiorrwill: be completed by. the raising off the. plunger 46;. which corresponds to the plunger Ii, at this. station. At station. 35L the handset: has been shown removed from the cradle with the plunger: 4'fl1raised. tolclose .the line contacts, while au station. 3.5: the handsetremains in the cradlet'o show: that the connection to this handset is-openedi An extension station49 for station 35' has alsobeen: shown. This station: is not: provided with any: keys for intercommunieating; but hasa connection 50 whichextends from this station over the line contact 5| through contact 52 at station 35'- toline 45*. It should be noted that in case the subscriber at station" 49- lifts' his handset f-rom'the cradle-asstation35 is engaged, contacts 5i will be closed and this subscriberwill-beable to listenein onthe conversation-between the subscribers at stations 35 'and 36. If, however, these subscribers require "privacy, that is, if they desire=to-carry on the conversation without havingtha subscriber at station 49 listen in; in case he should remove his 'hand'set fromthecradle; the subscriber at station 35 must operate his plunger 53,- which corresponds to plunger 5', by lifting it as-described in connection with Figs; 2to"6i This will open the c'ontact'52 and thus break'the connection between-lines 45 and '59 to prevent the subscriber at station 49 from listening in. Should-the subscriber at station 35 desire topermit'the subscriber at'station 49 to-listenin, hemerel'y d'epressesthe plunger '53 to again close the connection' through contact 52.

A more detailed description of actual circuits that may be used in arrangements of this sort will'now'bemade in connection with'Fig: 8; In this figure the station 35 and extension station 49' have been showrr with exclusion or secrecy contacts 56 controlled by-plunger 8 and corresponding forexample, to" the contacts'52 operated by plunger 53 at station 35 in'Fig; 7. A pick -upkey 5-1hasbeenshoWn-forline 59; This key may correspond-to" the left-hand key in group 31 and the line 59-may correspond to the line 45 in Fig 7.- Another key 65 and its-circuit have been shown foranother line-14 towhich the subscriber at station 35' may establish a connection. A holding key 6'! has also been shown which may be a keysimilarto the keys in the" group 31 of Fig; 7. This latter key isfor the purpose of holdingthe line 59 engaged:- if the subscriberat station 35' so desires; while-hemakes a connection through another line; for the purpose of later i transferring the. call to this station. A- ringing A cirand the tip conductor extending through contacts of the. holdingkey 61, the. keyr51: and the line relay. 64-. If: this line. 59. extends; to a central oflice, the subscriber. of line. 35. mayvoperate his dial 64: to. establish a;connection.to an automatic ofiice as'usual. If,,howe.ver, the line does not extendto' the central. oflice but to a particular subscriber in an intercommunicating system, say, for example the subscriber at station 35; he will operate a key, to signal the. subscriber by a ringing code. Any suitable system may be. em.-

.ployed forthispurpose.

In casethe subscriber. of line 35 desirestoprevent the subscriber at 49, that is the extension subscriber, fromlistening-in on the conversation; he will. operate contacts 55 by lifting. plunger 8 and. merely cuts: off. the: connection to this. sub.- scriber at 49. When the, subscriber of.1inei 35' replaces thehandset-ain the cradle; the-.plungers l and 8 will be restored to normal and':open,.respectively, the line contacts 62 and the secrecy contacts 55. Shouldxthe.subscriber:of; line 3541B.- sire to flash an operator at the:v central oflice in case the line 59 isconnected tolazcentral office, he may do so by manuallydepressingtheplunger'! which opens and closes the, linecontact- $2,011. if the plunger 8 has. not been operated to; exclude the set at 49 he may alternately'operate or re:- leasethe plunger8; These latter. operationsywill, ashereinbefore described, also, cause. the line: con;- tacts to be alternately openeolandi closed.v

If the subscriber of station 35 desires. to: hold the line 59 While. he. calls. another subscriber-,he will operate the holding key 61;. The relay 64" in the tip circuit, to the central office releases andzthe' key 6| closes a: circuit; over. the tip con-.- ductor. from the centralofficewinding 6.6. of relay 61, contacts of keys 5'! and. G l? over'the: subscribers loop contacts. of key 51, backltothe central ofiice over the; ring conductor. This energizes relay 61, and when relay 611' operatesgacircuit is established. across, the tip and ring conductors overthe armature and II'OIlt'COlltECU of this relay through windings 68 and 69; which. act as a holding bridge for. line 59;. Whenthe holdin key 6! is: operated, the key 5.1. is automatically released and the. winding. 55 of're'lay 651 will: be opened, while the relay fis'l 'will be held. operated over the tip and. ring conductors to the central office over windings. 68'and69, and-the station 35 disconnected from the line 59. The winding. 79- of the, relay 6! is used to balance. the line, to prevent cross-talk interference; The subscriber" at station 35 may now cal1.any other; subscriber. in the intercommunicating system". and: if. the connection to the central oificeis tobe transferred to. this. other subscriber; the pick-up key in this other subscriber-3s set corresponding. to line 59 will beoperated. This causesltheopera.- tion1of relay 64 which through its armature-and front" contact" short-circuits the windings 68. and 69; of relay 61. whichv now released. This, of. course, removes the holding bridge across; the line and conversatio-nmay take place between the second subscribers .stati'oniandztheparty on the line 59- at the central. office:

In case' theline 1T4; whichmay: be individual to station 35 from the centralioffi'ce, receives a call the" ringer 113 willoperate over the tip and ring conductors 1 as this: line is seizedtenotify the subscriber of said. station. 35; that. a. call is awaitingr him fromlthelcentral. oflice. He will then remove his handsetirom. thecradle and: operate key 50 to:connecthislline'toathis' calling line from the central oflice.

What is claimed is:

1. In combination, a telephone handset, a stand therefor having a cradle member in which the handset normally rests, a set of contacts, a plunger in said cradle movable under control of said handset for opening and closing said contacts, a second plunger movable independently of said first plunger for opening and closing said contacts, a second set of contacts, and means operated by a further movement of said second plunger for actuating said second set of contacts.

2. In combination, a telephone handset, a stand therefor having a cradle member in which the handset normally rests, a set of contacts, a plunger in said cradle movable under control of said handset for opening and closing said contacts, a second plunger movable between a normal position and a first operated position for opening and closing said contacts, a second set of contacts, and means operated by said second plunger when moved to a second operated position for actuating said second set of contacts without disturbing said first contacts.

3. In combination, a telephone handset, a stand therefor having a cradle member in which the handset normally rests, a set of contacts mounted in said stand, a reciprocating plunger in said cradle movable under control of said handset and also manually movable after the handset has been removed for actuating said contacts, a second set of contacts mounted in said stand, and a second reciprocating plunger mounted in said cradle independently of the first plunger which is movable under control of said handset and which is further movable manually while said handset is removed from said cradle to actuate said second set of contacts or to actuate said first set of contacts.

4. In combination, a telephone handset, a stand therefor having a cradle member'in which the handset normally rests, a set of contacts mounted in said stand, a reciprocating plunger in said cradle movable under control of said handset and also manually movable after the handset has been removed for actuating said contacts, a second set of contacts mounted in said stand, and a second reciprocating plunger in said cradle having a normal position and two operated positions, said second plunger being movable to its first operated position when the handset is removed from the cradle and movable manually from its first to its second operated position while the handset is removed to operate said second set of contacts and movable manually from either operated position to said normal position to release said first set of contacts.

5. In combination, a telephone handset, a stand therefor having a cradle member in which the handset normally rests, a set of contacts mounted in said stand, a reciprocating plunger in said cradle movable under control of said handset and also manually movable after the handset has been removed for actuating said contacts, a second reciprocating plunger mounted in said cradle independently of said first plunger which is movable in an upward or a downward direction under control of said handset and which is further movable in an upward direction manually while said handset is removed from the cradle, a second set of contacts actuated by said second plunger in response to its further upward movement, said second plunger being further movable in a downward direction manually while the handset is removed from the cradle to actuate said first set of contacts, and a collar on said second plunger to prevent the accidental movement of said plunger in said further upward direction after it has been moved manually in a downward direction to prevent the accidental operation of said second set of contacts.

6. In combination, a telephone handset, a stand therefor having a cradle member in which the handset normally rests, a set of contacts mounted in said stand, a reciprocating plunger in said cradle movable under control of said handset and also manually movable after the handset has been removed for actuating said contacts, a second set of contacts mounted in said stand, a second reciprocating plunger mounted in said cradle independently of said first plunger, and an extension on said second plunger, said second plunger and its extension being movable under control of said handset and being further movable while the handset is removed from said cradle to cause said extension to actuate said second set of contacts, said second plunger being further movable manually to restore both of said sets of contacts.

7. A handset, a stand for said handset, a first and a second set of contact springs in said stand, two plungers for said contact springs, a lever cooperating with one of said plungers and said first set of contact springs for operating said set of contact springs when the handset is removed from the stand, a second lever cooperating with the other of said plungers and said first lever for alternately restoring to normal and operating to actuated position said first set of contact springs when the handset is removed from the stand and the plunger is actuated manually, said second plunger being also manually movable when the handset is removed for actuating said second set of contact springs, while both of said plungers cooperate with said levers and said two sets of contact springs to restore them to normal position when the handset is replaced on the stand.

8. A handset, a stand for said set, two sets of contacts in said stand, two plungers for said contacts, a lever cooperating with one of said plungers and one of said sets of contacts, a second lever cooperating with the other plunger and with said first lever, means responsive to the removal of a handset from the stand for raising said first plunger under the control of said first lever for operating the associated contacts and for raising said second lever under control of said first lever to cause said second plunger to be raised, means responsive to the further raising of said second plunger for operating said second set of contacts, said levers, plungers and contacts being so arranged that if the first-mentioned plunger is lowered the first lever causes the associated contacts to be restored and if the second plunger is lowered the second set of contacts are restored and the second lever is lowered to cause the first lever to be lowered to restore the first set of contacts.

9. A telephone set including a base provided with a cradle portion, a hand set adapted to be supported upon said cradle portion, a pair of operating members each extending through said base and each operable in response to removal of said handset from said cradle portion and replacement of said handset upon said cradle portion, and switching means mounted within said base, said switching means including first and second operating levers, said first operating lever being operative independently of said second operating lever in response to the operation of one of said members and operative in response to the operation of said second operating lever,

said second operating lever being operative in response to the operation of the other of said members.

10. A telephone set including a base provided with a cradle portion, a hand set adapted to be supported upon said cradle'portion, a pair of operating members each extending through said base and each operable in response to removal of said hand set from said cradle portion and replacement of said hand set upon said cradle portion, switching means mounted within said base and comprising a plurality of contact springs, first and second levers, each of said levers being pivotally mounted within said base, said first lever being operative independently of said second lever in response to the operation of one of said members and operative in response to the operation of said second lever, said second lever being operative in response to the operation of the other of said members, and means controlled by the operation of said first lever for operating at least a portion of said contact springs between two circuit controlling positions.

11. A telephone set including a base provided with a cradle portion, a hand set adapted to be supported upon said cradle portion, a pair of operating plungers each extending through said base, each of said plungers being independently operable in one direction in response to removal of said hand set from said cradle portion and in the opposite direction in response to replacement of said hand set upon said cradle portion, whereby either of said plungers may be operated independently of the other in the event said hand set is supported at an angleupon said cradle portion, and switching means mounted within said base, said switching means including contacts and a an operating mechanism comprising a plurality of pivotally mounted interacting levers so arranged that said contacts are operated to predetermined circuit controlling positions in real of the hand telephone from said cradle and to replacement of the hand telephone upon said cradle, whereby either one of said operating members may be operated independently of the other in the event said hand set is supported at an angle upon said cradle, and switching means carried by said mounting, said switching means including first and second operating levers, said first operating lever being operative independent- 1y of said second operating lever in response to the operation of one of said operating members and operative in response to the operation of said second operating lever, said second operating lever being operative in response to the operation of the other of said operating members.

DOUGLAS H. KING. 

